1. Field of the Invention
The present invention relates to a treating device for endoscopes, such as basket type forceps to be inserted into the body cavity of a human subject and adapted to grasp a foreign matter such as calculus, and a high-frequency type snare for resecting polyps which are produced in the body cavity of the human subject.
2. Description of the Related Art
Known in the art is a basket type forceps which is adapted to grasp a foreign object, such as calculus, produced in the body cavity of a subject, such as in the bile duct and the urinary bladder. Such ordinary basket forceps 1 is configured as shown in FIG. 8. In FIG. 8, a grasp type basket member 4 is mounted on the distal end of an operation wire 3 which is inserted into and withdrawn from a flexible sheath 2. The basket member 4 has a plurality of elastic wires 5 with their base end portions fixed by a holding member 6 to the distal end of the operation wire 3. The forward ends of the respective elastic wires 5 are held together by a tip cap 7. Intermediate sections 9 of the wires are each defined by two outwardly folded sections 8 such that each extends parallel to the center axis of the basket member 4.
The basket member 4 can be moved back and forth relative to the open distal end of the flexible sheath 2 by moving the operation wire 3 back and forth by means of an operation device, not shown.
When the basket type forceps 1 is used, the flexible sheath 2 of the basket type forceps 1 is inserted through the channel of the endoscope to allow the basket member to extend via the distal end of the endoscope. At this time, when the basket member 4 is projected from the distal end of the sheath 2 into the body cavity of the subject, it is spread open by an elastic force of each elastic wire 5 by itself and the foreign matter can be trapped there by the basket member in the spread-open state. The foreign matter can be grasped by withdrawing the basket member 4 back into the distal end portion of the flexible sheath 2.
As seen from FIG. 8, the respective elastic wires 5 of the basket member 4 of the ordinary basket forceps 1 are less in the number of bent sections 8 and the intermediate sections 9 of the basket member 4 extend in a direction parallel to that in which the operation wire 3 is moved back and forth. For this reason, the basket member is liable to be collapsed into an irregular shape. In the narrow duct or tract of the patient's body, in particular, the basket member 4 is adequately not spread open, failing to grasp a foreign matter, such as the calculus.
The basket type forceps a set forth above is disclosed, for example, in the Published Examined Japanese Utility Model Application 61-9601 and Published Unexamined Japanese Patent Application 63-197443.